In a typical manufacturing system, it is often desirable to connect processes that manufacture the component parts to processes that assemble these parts into a finished product. Some of the benefits of this connection are: reduced labor for material handling; improved product quality, since the parts are not subjected to manual handling that may cause damage to the parts; and a reduction in the work-in-process inventory.
However, there are several potential obstacles to this type of connection that must be overcome. The parts may not lend themselves to conveyance directly, due to their size, shape, or presence of fragile features. The processes themselves may not lend themselves to direct connection. The parts manufacturing operation may be an intermittent process (i.e. part of the machine cycle the tooling is manufacturing the part and the remainder of the machine cycle the part is transferred to the next operation in the operation). The assembly operation, on the other hand, may be continuous motion (i.e. the tooling moves with the parts around a circular turret). When this occurs, it is not possible to time phase the output of the parts manufacturing operation to the input of the assembly operation. Also if too many operations are connected in series, without some time buffer, the overall efficiency of the manufacturing system will be reduced significantly.